• Title/Summary/Keyword: FEM, 유한요소법

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Comparative Study Between Finite Element Method and Limit Equilibrium Method on Slope Stability Analysis (사면안정해석에 있어서의 유한요소법과 한계평형법의 비교연구)

  • 이동엽;유충식
    • Journal of the Korean Geotechnical Society
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    • v.19 no.4
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    • pp.65-74
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    • 2003
  • This paper presents the results of a comparative study between FEM and LEM on slope stability analysis. For validation, factors of safety were compared between FEM and LEM. The results from the two methods were in good agreement. This suggests that the FEM with the shear strength reduction method can be effectively used on slope stability analyses. A series of analyses were then performed using the FEM for various constitutive laws, slope angles, flow rules, and the finite element discretizations. Among the findings, the finite element method in conjunction with the shear strength reduction method can provide reasonable results in terms of safety. Also revealed is that the results of FEM can be significantly affected by the way in which the type of constitutive law and flow nile we selected.

Comparison of analysis methods of estimating behavior of soil mass above rigid culvert (암거 상부지반의 거동 평가를 위한 해석법 비교)

  • Lee, Seung-Hyun
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.19 no.8
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    • pp.71-77
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    • 2018
  • In order to estimate behavior of soil mass which is located straight up of reinforced concrete culvert, Ritz method and FEM were applied and arching effects between the soil mass and adjacent soil were considered for the analyses. Analysis results obtained from the Ritz method and finite element method were compared with analytical solution. In the case of estimating nodal forces considered in FEM, caution is needed that shear stress depending on depth from ground surface should be reflected regardless of local coordinate system. Comparing the displacements computed from Ritz method with those of the analytic solution, it is seen that as the power of assumed displacement function increases, differences between the computed displacements and those of analytic solution decreases. It seems that displacements of FEM becomes closer to those of analytical solution as the number of elements are increased. It is seen that stresses computed from the Ritz method don't get closer to those of the analytic solution as the power of assumed displacement function. Stresses from FEM become closer to those of analytic solution as the number of elements are increased. Comparing the analysis results from the Ritz method and FEM with those of analytic solution, it can be seen that FEM is more reliable than Ritz method.

전계해석을 위한 유한 요소법의 활용

  • 정상진
    • 전기의세계
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    • v.36 no.10
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    • pp.713-721
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    • 1987
  • 본고에서는 유한요소법(FEM:Finite Element Method)을 활용하여 이방법의 장점인 복수법, 시변전계 및 직류이온장의 해석기법을 소개하고 그약점인 개방된 영역의 전계해석을 위한 경계이완법의 설명과 계산예, 그리고 유한요소법에 의한 전계계산법의 문제점과 향후전망을 언급코자 한다.

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Deformation Behaviors of Materials under Nanoindentation and Their Simulation by Three Dimensional FEM Analysis (재료의 나노압입변형과 그에 대한 3차원 FEM분석)

  • 김지수;양현윤;김봉섭;윤존도;조상봉
    • Proceedings of the Materials Research Society of Korea Conference
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    • 2003.11a
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    • pp.38-38
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    • 2003
  • 최근 나노기술의 발달과 더불어 나노재료에 대한 특성평가 요구가 높아지고 있고, 따라서 나노스케일로 재료의 기계적 거동을 분석할 수 있는 나노인덴테이션 기법이 심도있게 연구되고 있다. 본 연구에서는 나노인덴테이션을 이용하여 여러 가지 재료의 탄성 소성 변형 거동을 관찰 조사하고 이를 다시 유한요소법(FEM)으로 모사하여 해석하였다. 나노인덴테이션으로 재료 표면에 압입하여 탄소성 변형을 일으켰으며 이때의 가하중과 변형깊이를 측정하여 하중-변형 곡선을 얻었다. 매우 작은 접촉응력 조건하에서는 탄성변형의 비율이 매우 높았는데 하중-변형 곡선으로부터 재료의 나노 경도와 탄성 계수값을 얻을 수 있었다. 실험적으로 얻은 하중-변형 곡선을 3 차원의 유한요소법(FEM)을 이용하여 모사하였는데 상호간에 매우 근접한 결과를 얻을 수 있었다. 이 때 압자의 모양, 압입 깊이, 재료의 종류, 둥을 변수로 하여 여러 가지 조건하에서 압입실험을 하였으며 그 결과를 유한요소법으로 모사하였다.

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Stress Intensity Factor Calculation Using the Hybrid Formulation of Boundary and Finite Element Method (1st Report) (경계요소-유한요소 혼합법에 의한 균열선단의 응력강도계수 계산 (제1보))

  • In-Sik Nho;Chae-Whan Rim
    • Journal of the Society of Naval Architects of Korea
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    • v.35 no.4
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    • pp.38-45
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    • 1998
  • It is a tedious and excessive time consuming process to model the local area of crack tip part of structures in calculation of stress intensity factors by FEM. So, in this paper, the hybrid method of FEM and BEM approach was formulated to overcome this type of problems. The multi-domained BEM was adopted to simplify the modelling process of complex geometry and singularity characteristics of crack tip part and the ordinary FEM modelling was used in the rest part. The example calculations shows very good results compared with analytic solutions and other numerical method.

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Slope Stability Analysis Considering Seepage Conditions by FEM Using Strength Reduction Technique (강도 감소법에 의한 지하수위를 고려한 FEM 사면안정해석)

  • 김영민
    • Journal of the Korean Geotechnical Society
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    • v.20 no.8
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    • pp.97-102
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    • 2004
  • In this paper, a finite element based method far determining factor of safety of slopes which has certain advantages over conventional limit equilibrium methods is described. Particularly, the slope failure behaviour considering different seepage conditions is produced by finite element method using strength reduction technique. It is shown that both the failure mechanism and the safety factor that are analyzed by the FEM using strength reduction technique are an effective means of slope stability analysis. And the stability of a slope with rising water table and rapid drawdown are analyzed and the results are compared with the simplified Bishop Method of the Limit Equilibrium Methods.

Two-dimensional Resistivity Modeling Using Boundary Elements Method (경계 요소법을 이용한 2차원 비저항 모델링)

  • 김형수
    • The Journal of Engineering Geology
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    • v.6 no.3
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    • pp.119-130
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    • 1996
  • The theory and numerical technique using boundary elements method (BEM) are given to solve 2-dimensional resistivity problems. Potential distributions from homogeneous resistivity model and layered model are calculated by using BEM for a point source of current injection. The potential distributions of BEM are compared with those of finite difference method (FDM) and finite elements method (FEM). Among the three numerical methods to solve 2-dimensional resistivity problem, it is proved that BEM is more efficient tool than FDM and FEM in consideration of computing storage and time as weU as the accuracy of solutions.

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Analysis of Vibration of a Simple Plate In a Medium-to-High Frequency Range With Power Flow Finite Element Method (파워흐름유한요소법에 의한 중고주파수 영역에서 단순 평판의 진동 해석)

  • Seo, Seong-Hoon;Hong, Suk-Yoon;Kil, Hyun-Gwon;Huh, Young
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.16 no.2
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    • pp.125-131
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    • 2003
  • In this paper Power Flow Finite Element Method(PFFEM) has been implemented to analyze the vibration of a plate in mid and high frequency ranges. In order to solve the vibration energy governing equation in Power Flow Analysis(PFA), The Finite Element Method(FEM) was used as a numerical tool. It allowed one to predict the distribution of displacement and Intensity in the plate vibrating at mid and high frequencies. The results were compared with the analytical solutions and the approximate FEM solutions. The comparison showed that PFFEM can be an effective tool to analyze the structural vibration in mid and high frequency ranges.

Simulation of Corona Charging Process in Electret for Sensor Materials (센서재료용 일렉트렛트의 코로나 대전 과정 시뮬레이션)

  • Park, Geon-Ho
    • Proceedings of the Korean Society of Computer Information Conference
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    • 2012.07a
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    • pp.421-422
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    • 2012
  • 본 연구에서는 코로나 대전된 고분자의 열자격전류(Thermally Stimulated Current; 이하 TSC) 데이터를 기반으로 코로나 대전 과정을 유한요소법(Finite Element Method; 이하 FEM)을 이용하여 시뮬레이션하였다. $DC -5{\sim}-8[kV]$의 고전압을 고분자에 인가하여 형성시킨 일렉트렛트를 온도 범위 $-100{\sim}+200[^{\circ}C]$에서 얻은 TSC 데이터의 대전 과정을 조사하기 위하여 FEM으로 시뮬레이션을 수행하여 공간에서 코로나 대전 과정을 추정하였다.

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